A couple of years back I had a slow shower drain that would get better after pouring some drain cleaner down it, but get worse pretty quickly. I found myself frequently spending money drain cleaner. Then one day in the aisle with the drain cleaner I saw a rubber "hair trap" that you place over your shower drain to keep hair from going down. It was only $0.99 so I figured I would give it a try. Since that day a couple of years ago I have not had a need to buy any more drain cleaner. That $0.99 investment saved the cost of many, MANY, bottles!
Another example I have relates to auto repair. In the spring of 2008 I got a 2006 Saturn Ion. That summer I hit a pot hole that caused a flat tire. I had been going to Firestone for years, so I went there to get my new tires (had to replace both front tires). At that time they offered to me unlimited lifetime alignments for a one time $20 payment on top of the cost of a regular alignment. I did some simple math and quickly saw the benefit since the car was only 2 years old and I would more than likely need future alignments. I was able to take advantage of one free alignment when I went back in 2009 to get my rear tires replaced. Unfortunately my car saw an early death as it was totaled in a multi-car pile up on an icy highway. I fully intend to add the lifetime alignments to my new car.
With a little upfront investment I'm sure you too will find ways in your life to save money in the long run.